With Iran's economy in free fall after the US pulled out from the nuclear deal and escalated sanctions on Tehran, prices of imported medicines have soared as the national currency tumbled about 70 per cent against the dollar.

Even medicines manufactured in Iran are tougher to come by for ordinary Iranians, their cost out of reach for many in a country where the average monthly salary is equivalent to about $450.

Iran's health system can't keep up and many are blaming President Donald Trump's "maximum pressure" campaign for the staggering prices and shortages.

The sanctions have hurt ordinary Iranians, sending prices for everything from staples and consumer goods to housing skyward, while raising the spectre of war with the US.

Eight year old Taha Shakouri needs treatment for liver cancer.

Taha's mother, Laya Taghizadeh, says the hospital provides her son's medication for free - a single treatment would otherwise cost $1,380 at a private hospital. She adds the family is deeply grateful to the doctors and the hospital staff.

"We couldn't make it without their support," says the 30-year-old woman. "My husband is a simple grocery store worker and this is a very costly disease."

While the United States insists that medicines and humanitarian goods are exempt from sanctions, restrictions on trade have made many banks and companies across the world hesitant to do business with Iran, fearing punitive measures from Washington.

"Our biggest concern is that channels to the outside world are closed," said Dr. Arasb Ahmadian, head of the Mahak Children's Hospital, which is run through charity donations and supports some 32,000 under-16 children across Iran.

"Indeed, we are losing hope," said Ahmadian. "Medicines should be purchasable, funding should be available and lines of credit should be clearly defined in the banking system."

Official reports say Iran produces some 95 per cent of the basic medicines it needs and even exports some of the production to neighbouring countries.

But when it comes to more sophisticated medication and medicines for costly and rare illnesses and medical equipment, Iran depends heavily on imports. And though the state provides health care for all, many treatments needed for complicated cases are simply not available.

Pharmacist Peyman Keyvanfar says many Iranians, their purchasing power slashed, cannot afford imported medicines and are looking for domestically manufactured substitutes. "There has been a very sharp increase in the prices of medicines, sometimes up to three to four times for some," he said.

Many travel from rural areas to bigger cities in search of drugs for their loved ones.

Hosseingholi Barati, a 48-year-old father of three, came to Tehran from the town of Gonbad Kavus, about 550km to the northeast, looking for medication for his leukemia-stricken wife. He says he has spent $7,700 so far on her illness.

"It's a huge strain," he said. "I have sold everything I owned and borrowed money from family and friends."

Australian Associated Press